(a) Field of the Invention
The present invention relates to an electric fan, and more particularly, to one that detects the level of ambient suspended particles and starts the fan, emits ions and is provided with safety circuit brake feature.
(b) Description of the Prior Art
Air conditioning equipment is required at home and office for feeling comfortable and maintaining air quality. Electric appliances for ventilation and air purification are essentially available in the following types:.
1. Air Conditioner. It functions to regulate indoor temperature, dehumidify, ventilate and filter the air currents. In use, if the cooling/heating temperature is not properly set, the power consumption is excessively high. It is less convenient since the air filter made of sponge or plastic must be periodically removed and washed to clean.
2. Air Purifier. An earlier mechanical dust collector made of a plurality of rough and fine meshes of filter screens to collect dusts in the air in conjunction with a fan to circulate the air. However, extremely minute dusts are still able to penetrate the filter screens to prevent from being collected. Therefore, said mechanical dust collector has been waived for a long time. Recently, electric air purifier to collect dusts in the air has become popular. It operates on static by having parallel conductor plates with DC high voltage for the dust to become cations and negative electrons with the all the dusts carrying cations to be collected on the negative electrode plate and the dust collector provided on the electrode plate. However, the air purifier is weak to circulate the air; and usually a blower must be used if required.
3. Electric Fan. Fan blades rotate as driven by a motor. The electric fan is a must for every family particularly in tropic and sub-tropic areas since the hot summer could extend into the autumn. The electric fan comes available in the following types:
A. Ceiling Fan. Being suspended on the ceiling, the ceiling fan is usually comprised of three fan blades driven by a screened induction motor and contains variable contacts switch, current resistive coils and a speed regulator also functioning as a switch mounted on the wall at where accessible. However, the ceiling fan is good for air circulation without filtration and dehumidifying effects. Besides, it is not an easy task to clean the fan blades.
B. Stand Fan. Standing alone on the floor, the stand fan rotates without the necessity to move its stand, various control switches may be mounted to its stand and base, and allows readjustment of its height. However, it also fails to filter and dehumidify the air since it only cools the ambient temperature by circulating the air.
C. Wall-mounted Fan. A wall-mounted fan has its speed regulator and the fan blade separately provided with the former located at where accessible to facilitate the control. In some models, a rope is provided to control the speed regulator built in the wall mounted fan. Again, it does not provide air filter and dehumidification. Additionally, it is time and efforts consuming in cleaning the fan blades.
Nonetheless, the electric fan is still very popular for cheaper price and less power consuming though it fails the function of filtering and dehumidifying the air.
However, a further examination into the design of the electric fan of the prior art indicates that the insufficiency in its automation control. The electric fan is generally operated with a knob, push bottom or contact type of switch to start or stop the operation of the fan blades. It fails to achieve automated air cooling depending on the quality of the ambient air. Furthermore, it fails to purify the air and thus is difficult to meet consumer needs. Upon maintaining the electric fan, the screens and the fan blades must be removed. When the front screen is removed, the exposed fan blades may be actuated by accidentally touching the switch resulting in risk of cutting the hands of the user.
The primary purpose of the present invention is to provide an electric fan that detects the level of the ambient suspended particles and to automatically start the fan soonest the suspended particles reaches a certain level; is incorporated with an ion generator and provides safety power off function; characterized by that:
A smoke detector provided to the fan to detect density of suspended particles in the ambient air is wired to a CPU of a switch for control so that in case of higher density of suspended particles detected in the ambient air, the fan blades are automatically started to rotate for air cooling by the CPU; an ion generator is provided on the fan screen and a first conductor provided on the casing of the ion generator and connected to the CPU indicating off-position state; the first conductor is split in two ways respectively extending to an edge of a screen holder to form two contacts; a second conductor is provided on a rim where the screen holder engages a front screen in relation to those two contacts to form a conduction passage for ions generated from the ion generator to neutralize substance carrying hazardous cations along air circulation route created by the rotating fan blades so to achieve sterilization purpose. Once the front screen is removed, the CPU is in off-position due to the second conductor on the rim to disable the fan blades.